The present invention relates to masonry blocks used in construction and more particularly to the thermal insulation of such a block.
The current world-wide emphasis on energy conservation has prompted the proposal of numerous techniques for thermal insulation of buildings and other structures. Heretofore, buildings have been insulated in many different ways, presenting problems of varying sorts. One common method of building construction involves the use of masonry blocks which are of concrete casting. The blocks are bonded together to form the shell of the building. Insulation of such walls by applying layers of thermally insulative material to the surfaces of these walls to meet the required thermal insulation standards involves considerable expense and loss of interior building space. These problems have prompted numerous proposals which involve the placement of a thermal insulation medium within a concrete block. In this connection, attention is directed to U.S. Pat. Nos. 1,884,319; 2,199,112; 2,852,934; 2,933,146; 3,204,381; 3,546,833 and 3,704,562 for examples of such structure.
Another proposal involves the placement of U-shaped styrofoam inserts within the recesses of concrete blocks. Each insert is installed such that the legs of the insert lie parallel to one another flush against the inside and outside walls of the block and with the bight portion of the insert lying flush against a web of the block so as to extend transverse to the inside and outside surfaces of the block.
Among the disadvantages that can arise from the previous proposals are undue cost and less than optimum thermal insulation. For instance, in cases where insulative plates or irregular shape are employed, the steps necessary to properly shape the plate are expensive. Moreover, the blocks themselves must be of special, highly intricate design to adapt to the irregularly shaped insulation members. In some instances, substantial portions of the block must be removed, thereby presenting problems regarding structural strength of the blocks, and requiring an intricate, irregularly shaped insulative plate member. Those blocks which eliminate the advantage of thermally insulative air cells, or which unduly limit the ratio between air volume and concrete volume within the block, are incapable of achieving optimum insulative results. Blocks in which an extent of the insulation extends from the outer to the inner block wall increase the thermal through-path to an undesirable degree, thereby limiting the thermal insulative effects that can be achieved.
It would be desirable from an insulative standpoint, to restrict the rate of air circulation along the recesses or cavities within a wall formed by masonry blocks. The use of insulation inserts within the recesses generally does not prevent communication between the cavities of vertically superposed blocks forming the wall. The result is an extensive air space enabling a relatively large reate of air convection to occur within the wall. The use of multi-part inserts within the block recesses, such as disclosed in aforementioned U.S. Pat. No. 2,852,934, in an attempt to restrict internal air circulation, can be quite expensive in terms of material costs as well as man hours required in assembling the blocks.
It would be further desirable to provide a thermally insulated masonry block which minimizes the thermal through-path while maintaining the structural integrity of the block and without requiring an insulative plate of such irregular shape that it cannot be economically fabricated. For instance, masonry blocks which are longer than about 10 inches generally require one or more intermediate webs to provide the necessary strength and rigidity for withstanding vertical and eccentric loading. Consequently, insulation must be provided in the form of plural inserts or a single, highly irregularly shaped insert which, in either case, adds considerable expense in the fabrication and assemblage of the block. Moreover, the intermediate web defines a thermally conducting through-path from one side to the other of the block, thereby adding significantly to the overall thermal conductivity of the block.
It is therefore an object of the present invention to provide a novel thermally insulated masonry block.
It is another object of the present invention to provide an economical and easily assembled thermally insulated masonry block which incorporates insulative air cells.
It is a further object of the invention to provide a strong insulated masonry block which minimizes the thermal through-path.
It is still another object of the invention to provide a thermally insulated masonry block which is at least 10 inches in length, exhibits substantial strength for withstanding vertical and eccentric loading, requires only a single, rectangular insulative insert for insulating the entire cavity and exhibits minimal thermal conductivity.